an autobiography-第87节

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！


so　as　either　to　yield　the　most　gentle　pressure；　or　to　possess　the　power　of　compressing　to　upwards　of　twenty　thousand　tons；　the　only　limit　to　its　power　being　in　the　materials　employed　in　its　construction。

The　principle　of　this　enormously　powerful　compressing　machine　is　similar　to　that　of　the　Hydraulic　Press；　the　difference　consisting　principally　in　the　substitution　of　what　I　term　a　Hydraulic　Mattress　in　place　of　the　cylinder　and　ram　of　the　ordinary　hydraulic　press。　The　Hydraulic　Mattress　consists　of　a　square　or　circular　water…tight　vessel　or　flat　bag　formed　of　1/2…inch　thick　iron　or　steel　plates　securely　riveted　together；　its　dimensions　being；　say　15　feet　square　by　3　feet　deep；　and　having　semicircular　sides；　which　form　enables　the　upper　flat　part　of　the　Mattress　to　rise　say　to　the　extent　of　6　inches；　without　any　injury　to　the　riveted　joints；　as　such　a　rise　or　alteration　of　the　normal　form　of　the　semicircular　sides　would　be　perfectly　harmless；　and　not　exceed　their　capability　of　returning　to　their　normal　curve　when　the　6…inch　rise　was　no　longer　necessary；　and　the　elevating　pressure　removed。

＇image＇

The　action　of　this　gigantic　press　is　as　follows。　　The　Mattress　A　A　having　been　filled　with　water；　an　additional　quantity　is　supplied　by　a　force　pump；　capable　of　forcing　in　water　with　a　pressure　of　one　ton　to　the　square　inch；　thus　acting　on　an　available　surface　of　at　least　144　square　feet　surfacenamely；　that　of　the　upper　flat　surface　of　the　Mattress。　　It　will　be　forced　up　by　no　less　a　pressure　than　twenty　thousand　tons；　and　transfer　that　enormous　pressure　to　any　article　that　is　placed　between　the　rising　table　of　the　press　and　the　upper　table。　When　any　object　less　thick　than　the　normal　space　is　required　to　receive　the　pressure；　the　spare　space　must　be　filled　with　a　suitable　set　of　iron　flat　blocks；　so　as　to　subject　the　article　to　be　pressed　to　the　requisite　power。

As　before　stated；　there　may　be　many　processes　in　the　manufacturing　arts　in　which　such　an　enormous　pressure　may　be　useful；　and　this　can　be　accomplished　with　perfect　ease　and　certainty。　　I　trust　that　this　account　of　the　principles　and　construction　of　such　a　machine　may　suggest　some　employment　worthy　of　its　powers。　　In　the　general　use　of　the　Mattress　press；　it　would　be　best　to　supply　the　pressure　water　from　an　accumulator；　which　should　be　kept　constantly　full　by　the　action　of　suitable　pumps　worked　by　a　small　steam…engine。　　The　great　press　would　require　the　high…pressure　water　only　now　and　then；　so　that　it　would　not　be　necessary　to　wait　for　the　small　pump　to　supply　the　pressure　water　when　the　Mattress　was　required　to　be　in　action。


1840。　A　Tapping　Square；　or　instrument　by　which　Perfect　Verticality　of　　　　　　　the　Tapping　of　Screwed　Holes　is　insured。

＇image＇

The　letter　X　shows　how　Screws　are　frequently　made　when　tapped　in　the　old　mode；　the　letter　T　as　they　are　always　made　when　the　Tapping　Square　is　employed。


1840。　A　Mode　of　turning　Segmental　Work　in　the　Ordinary　Lathe

In　executing　an　order　for　twenty　locomotive　engines　for　the　Great　Western　Railway　Company；　there　was　necessarily　a　repetition　of　detail　parts。　　Many　of　them　required　the　labour　of　the　most　skilful　workmen；　as　the　parts　referred　to　did　not　admit　of　their　being　executed　by　the　lathe　or　planing…machine　in　their　ordinary　mode　of　application。　But　the　cost　of　their　execution　by　hand　labour　was　so　great；　and　the　risk　of　inaccuracy　was　so　common　（where　extreme　accuracy　was　essential）；　that　I　had　recourse　to　the　aid　of　special　mechanical　contrivances　and　machine　tools　for　the　purpose　of　getting　over　the　difficulty。　The　annexed　illustration　has　reference　to　only　one　class　of　objects　in　which　I　effected　great　saving　in　the　production；　as　well　as　great　accuracy　in　the　work。　　It　refers　to　a　contrivance　for　producing　by　the　turning…lathe　the　eighty　bands　of　the　eccentrics　for　these　twenty　engines。　　Being　of　a　segmental　form；　but　with　a　projection　at　each　extremity；　which　rendered　their　production　and　finish　impossible　by　the　ordinary　lathe；　I　bethought　me　of　applying　what　is　termed　the　mangle　motion　to　the　rim　of　a　face　plate　of　the　lay；　with　so　many　pins　in　it　as　to　give　the　required　course　of　segmental　motion　for　the　turning　tool　to　operate　upon；　between　the　projections　C　C　in　the　illustration。

＇image＇

I　availed　myself　of　the　limited　to…and…fro　horizontal　motion　of　the　shaft　of　the　mangle　motion　wheel；　as　it；　at　each　end　of　the　row　of　pegs　in　the　face　plate　（when　it　passes　from　the　exterior　to　the　interior　range　of　them）　in　giving　the　feed　motion　to　the　tool　in；　the　slide　rest；　〃turned〃　the　segmental　exterior　of　the　eccentric　hoops。　This　it　did　perfectly；　as　the　change　of　position　of　the　small　shaft　occurred　at　the　exact　time　when　the　cut　was　at　its　termination；that　being　the　correct　moment　to　give　the　tool　〃the　feed；　or　advance　for　the　taking　of　the　next　cut。　　The　saving；　in　respect　to　time；　was　10　to　1　in　comparison　with　the　same　amount　of　work　done　by　hand　labour；　while　the　〃truth〃　or　correctness　of　the　work　done　by　this　handy　little　application　of　the　turning…lathe　was　absolutely　perfect　I　have　been　the　more　particular　in　my　allusion　to　this　contrivance；　as　it　is　applicable　to　any　lathe；　and　can　perform　work　which　no　lathe　without　it　can　accomplish。　　The　unceasing　industry　of　such　machines　is　no　small　addition　to　their　attractions；　in　respect　to　the　production　of　unquestionably　accurate　work。


1843。　Invention　of　the　Steam　Hammer　Pile…driver。

Described　in　text；　p。　261。


1843。　A　Universal　Flexible　Joint　for　Steam　and　Water…pipes。

＇Image＇

The　chief　novelty　in　this　swivel　joint　is　the　manner　in　which　the　packing　of　the　joints　is　completely　enclosed；　thereby　rendering　them　perfectly　and　permanently　watertight。


1844。　An　Improvement　in　Blowing　Fans　and　their　Bearings。

The　principle　on　which　Blowing　Fans　act；　and　to　which　they　owe　their　efficiency；　consists　in　their　communicating　Centrifugal　action　to　the　air　within　them。

In　order　to　obtain　the　maximum　force　of　blast；　with　the　minimum　expenditure　of　power；　it　is　requisite　so　to　form　the　outside　rim　of　the　Fan…case　as　that　each　compartment　formed　by　the　space　between　the　ends　of　the　blades　of　the　Fan　shall　in　its　course　of　rotation　possess　an　equal　facility　of　exit　for　the　passage　of　the　air　it　is　discharging。　Thus；　in　a　Fan　with　six　blades；　the　space　between　the　top　of　the　blades　and　the　case　of　the　Fan　should　increase　in　area　in　the　progressive　ratios　of　1…2…3…4…5…6。

＇Image＇

If　a　Fan　be　constructed　on　this　common…sense　principle；　we　shall　secure　the　maximum　of　blast　from　the　minimum　of　driving　power。　　And　not　only　so；　but　the　humming　soundso　disagreeable　an　accompaniment　to　the　action　of　the　Fans　（being　caused　by　the　successive　sudden　escape　of　the　air　from　each　compartment　as　it　comes　opposite　the　space　where　it　can　discharge　its　confined　block　of　air）will　be　avoided。　　When　the　outer　case　of　a　Fan　is　formed　on　the　expanding　or　spiral　principle；　as　above　described；　all　these　important　advantages　will　attend　its　use。　As　the　inward　current　of　air　rushes　in　at　the　circular　openings　on　each　side　of　the　Fan…case；　and　would　thus　oppose　each　other　if　there　was　a　free　communication　between　them；　this　is　effectually　obviated　by　forming　the　rotating　portion　of　the　fan　by　a　disc　of　iron　plate；　which　prevents　the　opposite　in…rushing　currents　from　interfering　with　each　other；　and　at　the　same　time　supplies　a　most　substantial　means　of　fastening　the　blades；　as　they　are　conveniently　riveted　to　this　central　disc。　　On　the　whole；　this　arrangement　of　machinery　supplies　a　most　effective　〃Noiseless　Blowing　Fan。〃


1845。　A　direct　Action　〃Suction〃　Fan　for　the　Ventilation　of　Coal…Mines。

The　frequency　of　disastrous　colliery　explosions　induced　me　to　give　my　attention　to　an　improved　method　for　ventilating　coal　mines。　The　practice　then　was　to　employ　a　furnace；　placed　at　the　bottom　of　the　upcast　shaft　of　the　coal…pit；　to　produce　the　necessary　ventilation。　This　practice　was　highly　riskful。　　It　was　dangerous　as　well　as　ineffective。　　It　was　also　liable　to　total　destruction　when　an　explosion　occurred；　and　the　means　of　ventilation　were　thus　lost　when　it　was　most　urgently　required。　　The　ventilation　of　mines　by　a　current　of　air　forced　by　a　Fan　into　the　workings；　had　been　proposed　by　a　German　named　George　Agricola；　as　far　back　as　1621。　　The　arrangement　is　found　figured　in　his　work　entitled　De　Re　Metalicat；　p。　162。　　But　in　all　cases　in　which　this　system　of　forcing　air　through　the　workings　and　passages　of　a　mine　has　been　tried；　it　has　invariably　been　found　unsuccessful　as　a　means　of　ventilation。

As　all　rotative　Blowing　Fans　draw　in　the　air　at　their　centres；　and　expel　it　at　their　circumference；　it　occurred　to　me　that　if　we　were　to　make　a　communication　between　the　upcast　shaft　of　the　mine　and　the　centre　or　suctional　part　of　the　Fan　closing　the　top　of　the　upcast　shaft；　a　Fan　so　arranged　would　draw　out　the　foul　air　from　the　mine；　and　allow　the　fresh　air　to　descend　by　the　downcast　shaft；　and　so　traverse　the　workings。　　And　as　a　Suction　Fan　so　placed　would　be　on　the　surface　of　the　ground；　and　quite　out　of　the　way　of　any　risk　of　injurybeing　open　to　view　and　inspection　at　all　timeswe　should　thus　have　an　effective　and　trustworthy　means　for　thorough　ventilation。

＇Image